Surface treating appliance

ABSTRACT

A surface treating appliance, such as a vacuum cleaner, includes a main body, a surface treating head and a support assembly. The support assembly is rollably mounted to the main body for allowing the main body to be rolled along a surface. The support assembly includes a substantially continuous rolling support surface that extends in a direction perpendicular to the longitudinal axis of the main body and is symmetrical about the longitudinal axis. The arrangement of the support surface and support assembly assists maneuverability of the appliance. The support assembly may house a component of the appliance, such as a motor, and may accommodate a fluid inlet for receiving fluid flow and a fluid outlet for exhausting fluid.

FIELD OF THE INVENTION

This invention relates to a surface treating appliance, such as a vacuumcleaner.

BACKGROUND OF THE INVENTION

Surface treating appliances such as vacuum cleaners and floor polishersare well known. The majority of vacuum cleaners are either of the‘upright’ type or of the ‘cylinder’ type, called canister or barrelcleaners in some countries. An example of an upright vacuum cleanermanufactured by Dyson Limited under the name DC04 (“DC04” is a trademark of Dyson Limited) is shown in FIG. 1. The vacuum cleaner comprisesa main body 102 which houses the main components of the vacuum cleaner.A lower part 106 of the main body houses a motor and fan for drawingdirty air into the machine and the main body also houses some form ofseparating apparatus 104 for separating dirt, dust and other debris froma dirty airflow drawn in by the fan. The main body 102 also housesfilters for trapping fine particles in the cleaned airflow. A cleanerhead 108 is rotatably mounted, about points A, to the lower end of themain body 102. The axis about which the cleaner head rotates ishorizontally directed. A supporting wheel 107 is mounted on each side ofthe lower part 106 of the main body, in a fixed relationship to the mainbody 102. In use, a user reclines the main body 102 of the vacuumcleaner and then pushes and pulls a handle 116 which is fixed to themain body of the cleaner. The vacuum cleaner rolls along the floorsurface on the supporting wheels 107.

A dirty-air inlet 112 is located on the underside of the cleaner head108. Dirty air is drawn into the dust separating apparatus 104 via thedirty-air inlet 112 by means of the motor-driven fan. It is conducted tothe dust separating apparatus 104 by a first air flow duct. When thedirt and dust entrained within the air has been separated from theairflow in the separating apparatus 104, air is conducted to the cleanair outlet by a second air flow duct, and via one or more filters, andexpelled into the atmosphere.

Conventional upright vacuum cleaners have a disadvantage in that theycan be difficult to manoeuvre about an area in which they are used. Theycan be pushed and pulled easily enough, but pointing the cleaner in anew direction is more difficult. The cleaner can be pointed in a newdirection by applying a sideways directed force to the handle, eitherfrom standstill or while moving the cleaner forwards or backwards. Thiscauses the cleaner head to be dragged across the floor surface so thatit points in a new direction. The only articulation between the mainbody 102 and the cleaner head 108 is about horizontally directed axis A,which remains parallel with the floor surface. In some upright vacuumcleaners the supporting wheels 107 are mounted on the cleaner headrather than the main body. However, the main body is rotatably mountedto the cleaner head about a horizontally directed axis, as justdescribed.

Attempts have been made to increase the maneuverability of uprightvacuum cleaners. Some examples of upright vacuum cleaners with improvedmaneuverability are shown in U.S. Pat. No. 5,323,510 and U.S. Pat. No.5,584,095. In both of these documents, the vacuum cleaners have a basewhich includes a motor housing and a pair of wheels, and the connectionbetween the base and the main body incorporates a universal joint whichpermits rotational movement of the main body with respect to the baseabout an axis which is oriented perpendicular to the rotational axis ofthe wheels and inclined with respect to the horizontal.

A further, less common, type of vacuum cleaner is a ‘stick vac’, whichis so-called because it has a very slender stick-like main body. Anexample is shown in EP 1,136,029. Often, there is only a cleaner head atthe base of the machine, with all other components of the machine beingincorporated in the main body. While stick vacs are lighter weight andcan be easier to manoeuvre than traditional upright cleaners, theygenerally have a small dust separator, a lower power motor and smallerfilters, if any filters at all, and thus their improved maneuverabilitycomes with the drawback of a lower specification.

SUMMARY OF THE INVENTION

The present invention seeks to provide a surface treating appliance withimproved maneuverability.

The invention provides a surface treating appliance comprising a mainbody having a longitudinal axis, a support assembly which is attached tothe main body and arranged to roll with respect to the main body forallowing the appliance to be rolled along a surface, and a surfacetreating head, wherein the support assembly comprises one or morerotatable members having an outer surface which defines a substantiallycontinuous rolling support surface in the direction perpendicular to thelongitudinal axis of the main body, the support surface beingsymmetrical about the longitudinal axis of the main body.

Providing a substantially continuous support surface in the directionperpendicular to the longitudinal axis of the main body improvesmaneuverability and ensures a smooth transition between the forwardrunning and turning positions.

Preferably the support surface extends for a distance which is between50% and the full width of the main body. This allows the central portionof the assembly to have a flat surface, which aids forward runninghandling, and the end portions to have a reasonably gentle taper, whichaids handling during turning.

Advantageously, the support assembly houses a component of theappliance, such as a motor, in order to male efficient use of the spacewithin the support assembly. It can also increase the stability of theappliance.

The term “surface treating appliance” is intended to have a broadmeaning, and includes a wide range of machines having a head fortravelling over a surface to clean or treat the surface in some manner.It includes, inter alia, machines which apply suction to the surface soas to draw material from it, such as vacuum cleaners (dry, wet andwet/dry), as well as machines which apply material to the surface, suchas polishing/waxing machines, pressure washing machines, ground markingmachines and shampooing machines. It also includes lawn mowers and othercutting machines.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to thedrawings, in which:

FIGS. 1 and 2 show a known type of vacuum cleaner;

FIG. 3 shows a vacuum cleaner in accordance with an embodiment of theinvention,

FIGS. 4 and 5 show the vacuum cleaner of FIG. 3 in use;

FIGS. 6 and 7 show the connection between the cleaner head and main bodyof the vacuum cleaner of FIGS. 3 to 5;

FIGS. 8-10 show the roller assembly of the vacuum cleaner;

FIGS. 11 and 12 show the roller assembly in use;

FIG. 13 shows a cross-sectional view through the roller assembly of thevacuum cleaner;

FIGS. 14-16 show ways of housing a filter within the roller assembly;

FIG. 17 shows an alternative way of housing a motor and filter withinthe roller assembly;

FIGS. 18-21 show alternative shapes of roller assembly;

FIGS. 22-24 show a roller assembly with two rotating members;

FIG. 25 shows an alternative roller assembly with two rotating members;

FIG. 26 shows an alternative roller assembly with a larger number ofrotating members;

FIGS. 27 and 28 show alternative ways of connecting the main body to thecleaner head;

FIG. 29 a is a front perspective view of part of a mechanism forconnecting the main body to the cleaner head in a first (locked)position;

FIG. 29 b is a side view of the mechanism of FIG. 29 a in a second(unlocked) position; and

FIG. 29 c is a front sectional view of part of the mechanism of FIG. 29a along the line I-I′.

FIGS. 3-13 show a first embodiment of a vacuum cleaner 200 with a mainbody 210, a roller assembly 220 and a cleaner head 230.

DETAILED DESCRIPTION OF THE INVENTION

The cleaner head 230, as in a conventional upright vacuum cleaner,serves to treat the floor surface. In this embodiment, it comprises ahousing with a chamber for supporting a brush bar 232 (FIG. 6). Thelower, floor-facing side of chamber has an air inlet slot 233 and thebrush bar 232 is rotatably mounted in the chamber such that bristles onthe brush bar 232 can protrude through the inlet slot 233 and canagitate the floor surface over which the cleaner head 230 passes. Thebrush bar 232 is rotatably driven by a dedicated motor 242 positioned onthe cleaner head 230. A drive belt connects the motor 242 to the brushbar 232. This avoids the need to provide a driving connection betweenthe suction fan and the brush bar. However, it will be appreciated thatthe brush bar can be driven in other ways, such as by a turbine which isdriven by incoming or exhaust airflow, or by a coupling to the motorwhich is also used to drive the suction fan. The coupling between themotor and brush bar can alternatively be via a geared coupling. Inalternative embodiments the brush bar can be removed entirely so thatthe machine relies entirely on suction or by some other form ofagitation of the surface. For other types of surface treating machines,the cleaner head 230 can include appropriate means for treating thefloor surface, such as a polishing pad, a liquid or wax dispensingnozzle etc. The lower face of the cleaner head 230 can include smallrollers to ease movement across a surface.

The cleaner head 230 is connected to the main body 210 of the vacuumcleaner in such a manner that the cleaner head 230 remains in contactwith a floor surface as the main body is maneuvered through a wide rangeof operating positions, e.g. when moved from side-to-side or when themain body 210 is twisted about its longitudinal axis 211. A yoke 235connects the main body 210 to the cleaner head 230 in a manner whichwill be described in more detail below.

The main body 210 is rotatably connected to a roller assembly 220, whichlies at the base of the main body 210. The roller assembly 220 allowsthe apparatus to be easily pushed or pulled along a surface. The shapeof the roller assembly 220 and the connections between the main body 210and the roller assembly 220, and the roller assembly 220 and the cleanerhead 230, allow the apparatus to be more easily maneuvered thantraditional vacuum cleaners. On the left hand side the mechanicalconnection between the main body 210 and the roller assembly 220 is byan arm 540 which extends downwardly from the base of the main body 210.As shown in more detail in FIG. 13, arm 540 includes a sleeve 541 forreceiving a shaft 519 on which the roller shell 510 is rotatablymounted. On the right hand side of the machine, the connection betweenthe main body 210 and the roller assembly 220 is by the flow ducts 531,535, as best seen in FIG. 13.

The main body 210 has a handle 212 which extends upwardly from the topof the main body 210. The handle has a gripping section 213 by which auser can comfortably grip the handle and manoeuvre the apparatus. Thegripping section can simply be a part of the handle which is speciallyshaped or treated (e.g. rubberised) to make it easy to grasp, or it canbe an additional part which is joined to the handle at an angle to thelongitudinal axis of the handle, as shown in FIGS. 3-6.

The outer shell 510 of the roller assembly 220 is shown in more detailin FIGS. 8-10. Conveniently, the outer shell 510 comprises two halves,one of which is shown in FIG. 9, which can be secured together byfixings which locate in bores 586. In this embodiment, the overall shapeof the roller 220 resembles a barrel. Looking at the shape of the outersurface in the direction along the longitudinal axis, there is agenerally flat central region 580 and an arcuate region 585 at each endwhere the diameter, or width, of the shell 510 decreases. The central,flat region 580 has a constant diameter and extends for around 25% ofthe total length of the roller assembly. We have found that a flatcentral region aids a user in steering the machine along a straightline, since the machine will naturally run straight and is less likelyto wobble during backwards movements. The width of the central regioncan be increased or decreased as desired while still obtaining thebenefit of the invention. The arcuate outer regions 585 allow the mainbody to roll towards one side when a user wishes to steer the machine ina different direction. Ridges 511 are provided on the outer surface ofthe roller shell 510 to improve grip over surfaces. It is alsobeneficial to provide a non-slip texture or coating on the outermostsurface of the roller shell 510 to aid grip on slippery surfaces such ashard, shiny or wet floors. The length of the roller assembly issubstantially equal to the width of the main body 210 of the vacuumcleaner. The provision of a continuous support surface across the widthof the machine provides a reassuringly supportive feel to a user as themachine is maneuvered through a wide range of operating positions.Alternatives to this shape of roller assembly are discussed later.

Referring to FIG. 11, the shape of the roller surface is chosen suchthat the centre of mass 590 of the roller assembly always remains in aposition in which it serves to right the machine. To demonstrate this,FIG. 12 shows that even when the roller is turned onto its outermostedge, the centre of mass 590 will still lie to the right of a line 592drawn perpendicular to the surface, and thus the roller assembly willhave a tendency to return to a stable position.

The shape of the arcuate region 585 of the roller surface is alsoselected such that the distance between the centre of mass 590 of theroller assembly and a point on the surface of the roller shell increasesas one moves along the arcuate surface away from the central region 580.The effect of this shape is that it requires an increasingly greaterforce to turn the roller, as the roller is turned further from thenormal straight running position. The diameter of the roller shell 510at each end of its longitudinal axis determines the extent to which themain body can roll to one side. This is chosen such that there will besufficient clearance between the main body—and particularly the ducts531, 535 at the point at which they enter the roller assembly—and thefloor surface in this most extreme position.

The mechanical connection between the main body 210 and the cleaner head230 is shown in FIGS. 6 and 7. In this embodiment, the connectionbetween the main body 210 and the cleaner head 230 takes the form of ayoke 235 which is mounted to each end of the rotational axis 221 of theroller assembly 220. Further detail of the connection is shown in FIG.13. The yoke 235 can rotate independently of the main body 210. At theforward, central part of the yoke 235 there is a joint 237 with an arm243. Arm 243 joins the yoke 235 to the cleaner head 230. The other endof arm 243 is pivotably mounted to the cleaner head 230 about pivot 241.The joint 237 is of the type where the respective pipes can slideagainst one another. The plane of this jointed connection 237 is shownby line 238. The plane 238 of the joint is formed at a non-normal angleto the longitudinal axis of the arm 243. We have found that an anglewhich is substantially perpendicular to the floor surface (when themachine is in the forward running position), or further inclined fromthis position to what is shown in FIG. 6, works well. As arm 243 alsocarries airflow from the cleaner head 230, the joint 237 maintains anairtight seal as arm 243 moves with respect to yoke 235.

This arrangement of the pivotal mounting 241 of the yoke 235 and joint237, allows the main body 210 together with the roller assembly 220 tobe rotated about its longitudinal axis 211, in the manner of acorkscrew, while the cleaner head 230 remains in contact with the floorsurface. This arrangement also causes the cleaner head 230 to point in anew direction as the main body is rotated about its longitudinal axis211. FIG. 3 shows the position for forward or backward movement in astraight line while FIGS. 4 and 5 show the vacuum cleaner in twodifferent turning positions. In FIG. 3 the main body 210 is reclinedinto an operating position. The longitudinal axis 221 of the rollerassembly 220 is parallel with the floor and with the longitudinal axis231 of the cleaner head 230. Thus, the cleaner moves in a straight line.The main body can be moved anywhere between a fully upright position, inwhich the longitudinal axis 211 of the main body is perpendicular to thefloor surface, and a fully reclined position in which the longitudinalaxis 211 of the main body lies substantially parallel to the floorsurface.

FIG. 4 shows the vacuum cleaner turning towards the left. The main body210 is rotated anti-clockwise about its longitudinal axis 211. Thisraises the longitudinal axis 221 of the roller 220 assembly into aposition which is inclined with respect to the floor and which is facingtowards the left compared to the starting, straight running, position.The inclined joint 237 between the main body 210 and cleaner head 230causes the cleaner head 230 to point towards the left. The pivotableconnections between the yoke 235 and the main body 210, and between thearm 243 and the cleaner head 230, allow the cleaner head to remain incontact with the floor, even though the height of the yoke 235 varies asthe main body is rotated. The arcuate region 585 of the roller allowsthe body to roll into this position, while still providing support forthe main body 210. The extent to which the main body 210 is turned inthe anti-clockwise direction determines the extent to which the cleanerhead 230 moves from its forward facing position towards the left. Thesmaller diameter part 585 of the roller assembly not only allows themain body to roll onto one side, but tightens the turning circle of thevacuum cleaner.

FIG. 5 shows the vacuum cleaner turning towards the right. This is theopposite to what was just described for turning to the left. The mainbody 210 is rotated clockwise about its longitudinal axis 211. Thisraises the longitudinal axis 221 of the roller assembly 220 into aposition which is inclined with respect to the floor and which is facingtowards the right compared to the starting, straight running, position.The joint 237 between the main body 210 and cleaner head 230 causes thecleaner head 230 to point towards the right, while still remaining incontact with the floor. The arcuate region 585 of the roller allows thebody to roll into this position, while still providing support for themain body 210. The extent to which the main body 210 is turned in theclockwise direction determines the extent to which the cleaner head 230moves from its forward facing position towards the right.

The main body 210 houses separating apparatus 240, 245 which serves toremove dirt, dust and/or other debris from a dirty airflow which isdrawn in by the fan and motor on the machine. The separating apparatuscan tale many forms. We prefer to use cyclonic separating apparatus inwhich the dirt and dust is spun from the airflow of the type describedmore fully in, for example, EP 0 042 723.

The cyclonic separating apparatus can comprise two stages of cycloneseparation arranged in series with one another. The first stage 240 is acylindrical-walled chamber and the second stage 245 is a tapering,substantially frusto-conically shaped, chamber or a set of thesetapering chambers arranged in parallel with one another. In FIG. 3,airflow is directed tangentially into the upper part of a first cyclonicchamber 240 by duct 236. Larger debris and particles are removed andcollected in the first cyclonic chamber. The airflow then passes througha shroud to a set of smaller frusto-conically shaped cyclonic chambers.Finer dust is separated by these chambers and the separated dust iscollected in a common collecting region. The second set of separatorscan be upright, i.e. with their fluid inlets and outlets at the top andtheir dirt outlets at the bottom, or inverted, i.e. with their fluidinlets and outlets at the bottom and their dirt outlets at the top.However, the nature of the dust separating apparatus is not material tothe present invention and the separation of dust from the airflow couldequally be carried out using other means such as a conventional bag-typefilter, a porous box filter, an electrostatic separator or some otherform of separating apparatus. For embodiments of the apparatus which arenot vacuum cleaners, the main body can house equipment which isappropriate to the task performed by the machine. For example, for afloor polishing machine the main body can house a tank for storingliquid wax.

A fan and a motor for driving the fan, which together generate suctionfor drawing air into the apparatus, are housed in a chamber mountedinside the roller assembly 220.

A number of airflow ducts carry airflow around the machine. Firstly, anairflow duct connects the cleaner head 230 to the main body of thevacuum cleaner. This airflow duct is located within the left hand arm(FIG. 3) of yoke 235. Another duct 236 carries the dirty airflow fromthe yoke 235 to separating apparatus 240 on the main body. A changeovermechanism is provided for selecting whether airflow from the yoke 235,or a separate hose on the machine, is carried to the separatingapparatus 240. A suitable mechanism of this type is described more fullyin our International Application WO 00/21425.

Another airflow duct 531 connects the outlet of the separating apparatus245 to the fan and motor, within the roller assembly 220, and a furtherairflow duct 535 connects the outlet of the fan and motor to a postmotor filter on the main body 210.

One or more filters are positioned in the airflow path downstream of theseparating apparatus 240, 245. These filters remove any fine particlesof dust which have not already been removed from the airflow by theseparating apparatus 240, 245. We prefer to provide a first filter,called a pre-motor filter, before the motor and fan 520, and a secondfilter 550, called a post-motor filter, after the motor and fan 520.Where the motor for driving the suction fan has carbon brushes, thepost-motor filter 520 also serves to trap any carbon particles emittedby the brushes.

Filter assemblies generally comprise at least one filter located in afilter housing. Commonly, two or three filters are arranged in series inthe filter assembly to maximise the amount of dust captured by thefilter assembly. One known type of filter comprises a foam filter whichis located directly in the air stream and has a large dust retainingcapacity. An electrostatic or HEPA grade filter, which is capable oftrapping very small dust particles, such as particles of less than onemicron, is then provided downstream of the foam filter to retain anydust which escapes from the foam filter. In such a known arrangement,little or no dust is able to exit the filter assembly. Examples ofsuitable filters are shown in our International Patent Applicationnumbers WO 99/30602 and WO 01/45545.

In this embodiment, the filter or filters are both mounted in the mainbody 210.

FIG. 13 shows a detailed cross-section through the roller assembly 220.The outer shell 510, which has previously been shown in FIGS. 8-10, ismounted such that it can rotate with respect to the main body 210. Themain components within the roller shell 510 are a motor bucket 515 and afan and motor unit 520. On the left hand side, a support arm 540 extendsdown from the main body 210 alongside the end face of the roller shell.A shaft 519 passes through a hole in the centre of the end face of theroller shell 510. Shaft 519 is supported by a sleeve in part 541 of arm540. The roller shell 510 is rotatably supported on the shaft 519 bybearings 518. The shaft 519 extends along the longitudinal axis (androtational axis) of the roller shell 510 to locate within a pocket 525on the end face of the motor bucket 515. On the right hand side of themachine, the roller shell 510 has a much larger opening in its side faceso as to accommodate inlet 531 and outlet 535 ducts. The inlet andoutlet ducts 531, 535 serve a number of purposes. They provide supportboth for the roller shell 510 and the motor bucket 515 and they duct airinto/out of the motor bucket 515. The roller shell 510 is rotatablysupported on the motor bucket 515 by bearings 516. The motor bucket 515is mounted in a fixed relationship to the main body 210 and supportducts, i.e. the motor bucket 515 moves with the main body and thesupport ducts while the roller shell 510 can rotate around the motorbucket 515 when the machine is moved along a surface. The motor bucket515 fixes to the ducts 531, 535 by part 526. Ducts 531 and 535communicate with the interior of the motor bucket 515. Duct 531 deliversairflow from the separating apparatus 240, 245 on the main body 210directly to the inside of the motor bucket 515. Mounting the fan andmotor unit within the motor bucket 515 helps to reduce noise since themotor bucket 515 and the roller shell 510 form a double-skinned housingfor the fan and motor unit 520, with an air gap between the skins 510,515.

The fan and motor unit 520 is mounted within the motor bucket 515 at anangle to the longitudinal axis of the motor bucket 515 and the rollershell 510. This serves two purposes: firstly, it distributes the weightof the motor 520 evenly about the centre of the roller shell, i.e. thecentre of gravity of the fan and motor unit is aligned with the centreof the gravity of the overall roller assembly, and secondly, it improvesthe airflow path from inlet duct 531 into the fan and motor unit 520.The fan and motor unit 520 is supported within the motor bucket 515 byfixings at each end of its longitudinal axis. At the left hand side, thecavity between outwardly extending ribs 521 receives part 522 of themotor. On the right hand side, an outwardly tapering funnel 532 joinsinlet duct 531 to the inlet of the fan and motor unit 520. Thedownstream end of the funnel 532 has a flange 523 which fits around thefan and motor unit 520 to support the fan and motor unit 520. Furthersupport is provided by a web 524 which surrounds the fan and motor unit520 and fits between flange 523 and the inner face of the motor bucket515. The funnel 532 also ensures that incoming and outgoing airflowsfrom the motor bucket are separated from one another.

Air is carried to the fan and motor unit 520 within the roller assemblyby inlet duct 531 and funnel 532. Once airflow has passed through thefan and motor unit 520, it is collected and channeled by the motorbucket 515 towards the outlet duct 535. Outlet duct 535 carries theairflow to the main body 210.

Outlet duct 535 connects to the lower part of the main body 210. Part552 of the main body is a filter housing for the post motor filter 550.Air from duct 535 is carried to the lower face of the filter housing,passes through filter 550 itself, and can then exhaust to atmospherethrough venting apertures on the filter housing 552. The ventingapertures are distributed around the filter housing 552.

A stand assembly 260, 262 is provided on the machine to provide supportwhen the machine is left in an upright position. The stand assembly isarranged so that it is automatically deployed when the main body 210 isbrought towards the fully upright position, and is retracted when themain body 210 is reclined from the fully upright position.

There is a wide range of alternative configurations to what has justbeen described and a number of these will now be described.

In the embodiment just described, airflow is ducted into and out of theroller shell 510, from one side of the roller shell, and the spacewithin the roller shell 510 is used to house a motor bucket 515 and thefan and motor unit 520. Other uses can be made of the space inside theroller shell 510 and FIGS. 14-16 show some of these alternatives. Ineach of FIGS. 14-16 a filter is housed within the roller shell 600. InFIG. 14 a cylindrical filter assembly 605 is housed within the rollershell 600 with its longitudinal axis aligned with that of the rollershell. An inlet airflow duct 601 carries air from the outlet of theseparating apparatus 240, 245 on the main body 210 of the vacuum cleanerto the interior of the roller shell 600. An outlet airflow duct 602carries airflow from the interior of the roller shell 600. The rollershell is rotatably mounted about ducts 601, 602 on bearings 603. Filter605 is supported by the ducts 601, 602. In use, air flows from inletduct 601, around the outside of filter 605 and radially inwards, throughthe filter medium, to the central core of the filter 605. The air canthen flow along the core and exit the roller shell 600 via outlet duct602.

In FIG. 15, a filter 610 is mounted transversely across the roller shell600. The inner surface of the roller shell 610 can be provided withsuitable fixings for securing the filter 610 in place. The air flow inFIG. 15 is much simpler. Air flows from inlet duct 611, through theinterior of the roller shell 600, through filter medium 610 and thenleaves the roller shell via outlet duct 612. The filter material caninclude foam and filter paper which is either flat or pleated toincrease the surface area of filter medium presented to the airflow.

FIG. 16 is similar to FIG. 14 in that a filter 625 is mounted with itslongitudinal axis aligned with that of the roller shell 600. The notabledifference is that air can exhaust directly to atmosphere from viaapertures 608 in the roller shell 600. Duct 622 provides mechanicalsupport for the roller shell and does not carry airflow.

To gain access to the filter a hatch can be provided in the roller shell600. However, as many filters are now lifetime filters, which do notrequire changing during the normal lifetime of the machine, it can beacceptable to fit the filter within the roller shell in a lessaccessible manner.

In each of these embodiments it is possible to provide an inner shellwithin the roller shell 600, in the same manner as motor bucket 515 wasprovided in FIG. 13. The inner shell will be sealed to the inlet andoutlet ducts, thus alleviating the sealing requirements of the rollershell.

In FIGS. 14 and 15 the exhaust duct can be mounted on the same side ofthe roller assembly as the inlet duct. The two ducts can be mounted in aside-by-side relationship, as previously shown in FIG. 13, or one ductcan surround the other duct, as shown later in FIG. 18.

FIG. 17 shows an alternative arrangement for mounting a fan and motorunit inside the roller assembly. As with the arrangement shown in FIG.13, there is a roller shell 700 with a motor bucket 715 mounted inside,and the roller shell 700 can rotate around the motor bucket 715. Aninlet airflow duct carries air to the fan and motor unit 520. However,in this embodiment, a filter 710 is positioned downstream of the fan andmotor, inside motor bucket 715. Air is exhausted directly from theroller assembly via an outlet 705. The outlet 705 is positioned next tothe support arm 702 on the hub of roller 700. This means that air outlet705 remains stationary as the roller 700 rotates. As a furtheralternative, the filter 710 could be omitted altogether. Where the motoris a brushless motor, such as a switched reluctance motor, there willnot be any carbon emissions from the motor and thus there is less needfor a post-motor filter. When air is directly exhausted from the rollerassembly in this manner there is an option of still providing the secondsupport arm 702 (which does not carry airflow), or the second supportarm 702 can simply be omitted and all of the support for the rollerassembly is provided by the first support arm.

Alternatively, or additionally, the roller assembly may house otheractive components of the appliance, such as a motor for driving asurface agitating device and/or a motor for driving wheels so that theappliance is self-propelling along the surface. In another alternativeembodiment, separating apparatus can be housed inside the rollerassembly, such as the cyclonic separating apparatus hereinbeforedescribed.

Shape of Roller

The embodiment shown in FIGS. 3-13 has a barrel shaped roller with aflat central region and tapering end regions. FIGS. 18-21 show a rangeof alternative roller shapes. This list is not intended to be exhaustiveand other shapes, not illustrated, are intended to fall within the scopeof the invention. The roller, or set of rolling members, can have asubstantially spherical shape, as shown in FIG. 18, or a spherical shapewith truncated faces 811, 812 as shown in FIG. 19. A true sphere has theadvantage that the force required to turn the roller remains constant asthe main body is turned from a straight running position, since thedistance between the centre of mass and surface remains constant. Also,because the distance between the geometric centre of the roller assemblyand the outer surface remains constant, the height of joint 237 betweenyoke 235 and the cleaner head 230 remains constant as the main body isrotated about its longitudinal axis 211. This simplifies the jointingrequirements between the main body and the cleaner head 230.

Truncating the end faces of the sphere has the benefits of reducing thewidth of the roller and removing a part of the surface which is notlikely to be used. Also, the ducts entering and leaving the roller arelikely to make contact with the floor if the machine were allowed toroll onto the outer most part of the surface. FIG. 20 shows a spherewith a central flat region 813 and FIG. 21 shows a central ring 814 ofconstant diameter with a hemisphere 815, 816 at each end.

The embodiments shown above provide a roller assembly with a singlerolling member. A larger number of parts can be provided. FIGS. 22-24show embodiments where the roller assembly comprises a pair ofshell-like parts 731, 732. Each part is independently rotatable. Part731 is rotatable about a combined support arm and duct 735, 736 and part732 is rotatable about combined duct and support arm 740. A motor bucket742 fits within the rotatable parts 731, 732 and supports fan and motorunit 743. An advantage in providing two shell-like parts 731, 732 isthat the space between parts 731, 732, in the direction along therotational axis of the parts 731, 732, can be used to accommodate a duct745 which carries air from the cleaner head 230 to the interior of theroller assembly, a mechanical connection between the cleaner head andthe roller assembly, or both of these features. In FIGS. 23 and 24 acombined mechanical connection and air duct 741 is connected to thefront of the motor bucket 742, in the space between parts 731, 732,passes inside the motor bucket 742, and then extends in a directionwhich is aligned with the rotational axis of part 732. Outlet duct 740provides mechanical support for part 732 as well as carrying air flow tothe main body of the vacuum cleaner. There are two ways in which therequired degree of articulation between the duct 745 and main body canbe achieved. Firstly, duct 745 can be pivotably mounted to the motorbucket 742. Secondly, the duct 745 can be rigidly mounted to the motorbucket 742 and the motor bucket 742 is rotatably mounted to the supportarms 735, 736 and 740.

The space between the two rotatable parts 731, 732 can be used toaccommodate a driving connection between a motor inside the motor bucket742 to a brush bar on the cleaner head 230. The driving connection canbe achieved by a belt and/or gears.

As shown in FIG. 25, the rotational axis of each rolling member need notbe aligned with one another. Here the rotational axes 821, 822 ofrolling members 823, 824 are each inclined inwardly from the vertical.

It is also possible to provide three or more rotatable parts. Indeed,there can be a much large number of adjacent parts which are each freeto rotate about an axle as the apparatus is moved along a surface. Theset of rotatable parts can all be mounted about a linear axis, with thediameter of each part decreasing with distance from the central regionof the axis. Alternatively, as shown in FIG. 26, the rotatable parts 825can all have the same or similar size and are mounted about an axis 826which has the shape which is required from the lower surface of theroller assembly. The rotatable parts 825 can be small, solid parts whichare mounted about a shaft, or they can be larger, hollow, annular partswhich are rotatably mounted about a housing whose longitudinal axis isnon-linear. The housing can accommodate a motor or filter, as previouslydescribed.

In each embodiment, the shape of the roller assembly, or set ofrotatable parts, defines a support surface which decreases in diametertowards each end of the rotational axis so as to allow the main body toturn with ease. As in the embodiment described above, it is preferredthat the central region of the rotatable part, or set of parts, issubstantially flat as this has been found to increase stability of theapparatus when it is driven in a straight line.

Connection Between Main Body and the Cleaner Head

Referring again to FIGS. 6 and 7, the connection between the main body210 and the cleaner head 230 is via a yoke 235 which has a joint 237formed at a plane which is inclined to the longitudinal axis of arm 243.The angle of the plane 238 in which the joint lies can be varied fromwhat is shown here. We have found that forming the joint 237 such thatthe plane 238 of the joint is normal with the longitudinal axis of thearm 243 is acceptable, but does not provide the full advantage of theinvention since rotating the yoke does not cause arm 243 (and hence thecleaner head 230) to turn. Forming the joint 237 such that the plane 238of the joint is inclined with the longitudinal axis of the arm 243, andsubstantially perpendicular to the floor surface (with the machine in aforward running position) provides good results. Inclining the plane 238still further to what is shown in FIG. 6, or further still, increasesthe extent to which cleaner head 230 will move when the main body isrotated about its longitudinal axis.

The connection between arm 243 and cleaner head 230 is shown in FIGS. 6and 7 as a true pivot with a shaft. We have found that while some degreeof pivotal movement is required at this position, this movement can beachieved by a more relaxed form of jointed connection.

FIG. 27 shows an alternative form of the connection between the mainbody 210 and the cleaner head 230. As previously, there is a yoke 235,each end of the yoke connecting to the main body about the rotationalaxis 221 of the roller assembly. Also, there is a short arm 243 which ispivotably connected to the cleaner head 230. The difference is at theforward face of the yoke 235. Instead of a rotating joint which isinclined at an angle to the longitudinal axis of the arm 243, there is arotating joint which is formed at an angle which is normal to thelongitudinal axis of the aim 243 and the part of the yoke 235 whichjoins arm 243 at joint 852 has an elbow shape 851. The combination of anelbow shape and a joint at a normal angle has been found to beequivalent to providing a joint at an inclined angle. This alternativescheme can be more cumbersome to implement as it requires more spacebetween the cleaner head 230 and the roller assembly 220.

Part of a further alternative connection between the main body and thecleaner head is illustrated in FIGS. 29 a, b and c. As before, theconnection comprises a yoke 901, each end portion 902, 903 of the yokebeing connectable to the main body about the rotational axis of theroller assembly. The central portion of the yoke comprises a joint 904that is connectable to a cleaner head (not shown), either directly orvia an intermediate arm, such as those illustrate in FIGS. 7 and 27. Theconnection further comprises a locking arm 905 that is pivotablyattached to the yoke 901 at the end portions 902, 903, and extends alongit. The locking arm 905 has a central extending portion 906, which maybe rigid with respect to the arm or may be pivotably attached to it. Thecentral portion 906 can be received by a complementary notch arrangement907 in the joint 904, so as to “lock” the joint and prevent it frombeing rotated when, for example, the appliance is in the standingposition. The linkage is shown in the locked position in FIG. 29 a.Thus, the cleaner head itself provides extra stability to the appliancein the standing position. Resilient means (not shown) may be provided tobias the central portion 906 of the locking arm 905 towards the jointwhen the appliance is in the standing position, so as to provideautomatic locking of the joint.

When it is desired to use the appliance, the user reclines the main bodyof the appliance. The connection is arranged so that, when the main bodyis tilted backwards, the locking arm 905 rotates with respect to theyoke 901 and is raised to the extent that the central portion 906 of thelocking arm is lifted out of the notch 907, thereby unlocking the joint904 for rotation. The linkage is shown in the unlocked position in FIGS.29 a and 29 c. Resilient means may be provided to assist the raising ofthe locking arm 905. Motion of the locking arm 905 may be influenced bymotion of the stand assembly 260, 262 during reclining and righting ofthe appliance.

The central portion 906 of the locking arm 905 may be provided withdownwardly-extending tines 908 a, b, c, that are received by respectivenotches 909 a, b, c, in the joint 904. The tines 908 are arranged to beflexible so that, if the user attempts to apply rotational force to thelocked joint beyond a predetermined limit, at least one of the tinesdeforms. The applied force then causes the tines 908 to pop out of thenotches 909, thereby freeing the joint 904 for rotation. This featureprevents the connection from being damaged in the event that excessiveforce is applied to the joint while the appliance is in the standingposition. If the appliance is returned to the standing position, thecentral portion 906 of the locking arm 905 is urged back into the lockedposition in the joint by the force of the resilient means.

The supports between the main body and the cleaner head do not have tobe rigid. FIG. 28 shows a pair of flexible support tubes 831, 832 whichconnect the roller assembly 830 to the cleaner head 833. Where flexibletubes are used, the cleaner head can freely remain in contact with thefloor surface as the main body is rolled from side-to-side or twistedabout its longitudinal axis. The use of flexible tubes in this manneravoids the need for a more complex arrangement of mechanical jointsbetween the main body and the cleaner head.

Of course, a combination of connection mechanisms can be employed.

In each of the embodiments shown and described above airflow ducts havebeen used, wherever possible, to provide mechanical support betweenparts of the machine, e.g. between the main body 210 and roller assembly220 and between the cleaner head 230 and main body 210 by yoke 235. Thisrequires the ducts to be suitably sealed. It should be understood thatin each embodiment where the features of a flow duct and mechanicalsupport have been combined, separate supports and flow ducts can besubstituted in their place. The flow duct can be a flexible or rigidpipe which lies alongside the mechanical support.

Although there are advantages in housing the motor inside the rollerassembly, in an alternate embodiment, the fan and motor can be housed inthe main body. This simplifies the ducting requirements on the machinesince there only needs to be a duct from the cleaner head to the mainbody. Support arms are still required between the main body and theroller assembly and between the main body and the cleaner head.

While the illustrated embodiment shows a vacuum cleaner in which ductscarry airflow, it will be appreciated that the invention can be appliedto vacuum cleaners which carry other fluids, such as water anddetergents.

1. A surface treating appliance comprising: a main body having alongitudinal axis; a support assembly which is connected to the mainbody and arranged to rotate with respect to the main body for allowingthe appliance to be rolled along a surface; and a surface treating headconnected to the main body; wherein the support assembly comprises oneor more rotatable members having outer surfaces which together form asingle substantially continuous rolling support surface in a directionperpendicular to the longitudinal axis of the main body, the supportsurface being symmetrical about the longitudinal axis of the main body.2. An appliance according to claim 1 wherein the support surface extendsfor a distance which is at least 50% of the width of the main body. 3.An appliance according to claim 1 wherein the support surface extendsfor a distance which is at least 75% of the width of the main body. 4.An appliance according to claim 1 wherein the support surface extendsfor a distance which is substantially equal to the width of the mainbody.
 5. An appliance according to claim 1 wherein the diameter of thesupport assembly is less at an end portion than at a central portion. 6.An appliance according to claim 1, 2, 3, 4 or 5 wherein the supportassembly has at least one rotational axis which is transverse to thelongitudinal axis of the main body.
 7. An appliance according to claim 6wherein the distance between the geometric centre of the assembly andthe outer surface is greater at an end portion than at a centralportion.
 8. An appliance according to claim 7 wherein the centralportion of the support assembly has a substantially constant diameter.9. An appliance according to claim 6 wherein the support assembly issubstantially spherical in shape.
 10. An appliance according to claim 7wherein the support assembly comprises a plurality of rotatable membersarranged so that members at the central portion of the support assemblyextend lower than members at each end portion.
 11. An applianceaccording to claim 10 wherein at least part of the support assembly hasa curved rotational axis.
 12. An appliance according to claim 7 whereinthe centre of mass of the support assembly is arranged to return thesupport assembly to a normal position when the support assembly istilted away from that position.
 13. An appliance according to claim 7wherein the rotatable member, or members, are hollow and are mountedaround a chamber.
 14. An appliance according to claim 13 wherein thesupport assembly houses at least one component for the appliance.
 15. Anappliance according to claim 14 wherein the component is mounted withinthe support assembly such that the support surface rotates around thecomponent.
 16. An appliance according to claim 14 further comprising ashell, mounted within the support assembly, for supporting thecomponent, and wherein the rolling support surface of the supportassembly is rotatably mounted about the shell.
 17. An applianceaccording to claim 14 wherein the support assembly comprises a fluidinlet for receiving fluid flow, a fluid outlet for exhausting fluid andthe component comprises a device for acting on the fluid flow receivedthrough the inlet.
 18. An appliance according to claim 17 wherein thedevice for acting on the fluid flow comprises a suction generator. 19.An appliance according to claim 14 wherein the component comprises amotor for driving a further component of the appliance.
 20. An applianceaccording to claim 19 wherein the further component comprises a surfacetreating device.
 21. An appliance according to claim 14, furthercomprising a linkage between the main body and the surface treatinghead, wherein the linkage is arranged such that rotating the main bodyabout its longitudinal axis causes the surface treating head to turn ina different direction.
 22. An appliance according to claim 21 whereinthe linkage is arranged to allow the surface treating head to remainsubstantially in contact with the surface as the main body is rotatedabout its longitudinal axis.